The present invention is a device for dispensing at least one product, in addition to water, through a shower head. More particularly, it is a device that conserves product, by using a coaxial shower nozzle that has separate flow channels for water and the product selected by a user.
The prior art contains a variety of shower devices that mix water and a product, such as soap or shampoo, in a shower head. One such device as taught by Greenhut, et al in U.S. Pat. No. 4,358,056 uses a coupling that produces a venturi effect to pass shower water and draw in a liquid product from a reservoir. Garneys in U.S. Pat. No. 5,333,789 teaches the use of an insert located between a water inlet pipe and a shower head that diverts the water to a reservoir containing product where the water mixes with the product before entering the shower head. The device taught by Lacy in U.S. Pat. No. 4,219,158 uses a mixer disc in a shower head to intimately water spray with one or two products in a reservoir. The device taught by Davison in U.S. Pat. No. 4,218,013 uses an insert between a shower head and a water inlet pipe to introduce a product stored in a reservoir and selected by a valve into the water stream entering the shower head.
Most other shower head mixing devices, such as the shower soap dispenser taught by Bishop in U.S. Patent Application US 2013/0186971, use a vacuum-Venturi effect to draw a product into the water flow. This requires a very high vacuum to operate properly and generates noise because of the high velocity of fluid traveling across the Venturi. The instant invention uses pressure to force the flow of product into the shower head to eliminate the noise from the Venturi operation. Conventional shower hear mixing devices do not allow for fine regulation of the concentration of a product in the water flow leaving a shower header. Too often the product is too dilute in the stream leaving the shower head. This wastes the product and the water in the stream. In contrast, the instant invention has a two-stage coaxial shower head that allows for either conventional water flow or a low rate flow of water and product with just enough water to spray the product on the user's body. This eliminates undue dilution of the product.